The Department of Homeland Security informed PSTA staff in a conference call that the agency might have to return the money because the radio and television ads didn't promote security awareness, PSTA chief executive officer Brad Miller said in an email to his board of directors Friday.

"After I heard this, I immediately decided not to wait any further while DHS would likely delay a final decision, and we sent the grant funds back in a check on Wednesday," Miller wrote.

In an interview, Miller said DHS staffers said during the call that the commercials did not meet the requirements for an "anti-terrorism" campaign. He said that was the first time the department used that phrase to describe the grant requirements.

Miller said he stands by the "PSTA Cares" commercials that he said were created on the general guidelines included in the Transit Security Grant Program. He said the department failed to provide specific criteria despite repeated requests from the PSTA.

"I've been frustrated all along with the lack of communication from DHS on this," Miller said. "We don't believe we've violated anything. We just did not have the guidance."

The DHS did not respond to an email and phone call Friday.

Miller's move comes after U.S. Rep. David Jolly, R-Indian Shores, met with DHS officials to pass along complaints from constituents who said the commercials, rather than promote security awareness, were feel-good ads that promoted the transit agency and the Greenlight Pinellas transit referendum.

The three 30-second television ads featured the Greenlight Pinellas logo and website at the end, but according to Miller, DHS officials said that did not factor into their review.

The grant money was awarded in 2011. After that, Miller said, the agency tried for six months without success to get input on how to develop the ads. In December of that year, the authority awarded the ad contract to a consulting firm "believing all along that a message of positively portraying how PSTA was safe and secure to different markets was in compliance," Miller wrote in the email to his board.

One of the ads features Eva, a college student and office intern.

"She knows PSTA cares about her time and her security," the narrator says at one point in the ad. "Eva can use a computer or a phone to check real-time bus information to see exactly where her PSTA bus is and when it will arrive."

In another ad, the narrator touts the authority's diesel-electric hybrid buses, then says that Phillip, the young professional featured in the ad, "knows PSTA is providing him with safe and secure bus service."

Miller said his agency asked the DHS to review ads, but it refused. The ads began airing in July 2013 and about 95 percent had stopped running by Dec. 10, when the Pinellas County Commission approved placing the Greenlight Pinellas referendum on the Nov. 4 ballot, Miller said.

In a recent interview, Jolly said several constituents contacted him in late April or early May to complain. He asked them to gather the materials, which he gave to DHS officials in a meeting on May 29.

Jolly said he shared their concerns that federal funds might have been misused to promote Greenlight.

"This is about making sure tax dollars are being used correctly," Jolly said in a statement Friday. "I applaud the decision by PSTA to remove any question of controversy regarding the use of taxpayer money."

This is the second time the PSTA's spending has been called into question. Earlier this year, state Sen. Jeff Brandes asked the Florida Department of Transportation to investigate whether the PSTA's Greenlight informational materials illegally advocated for its passage. The agency concluded it did not.

County Commissioner and PSTA board Chairman Ken Welch said he supports Miller's decision to repay the money.

"They're good ads," Welch said. "They do talk about why transit is safe. This was meant to be a distraction, and as far as I'm concerned, it's not going to be."